Then I saw a Lamb, looking as if it had been slain, standing at the center of the throne, encircled by the four living creatures and the elders...

The Lamb had seven horns and seven eyes, which are the seven spirits of God sent out into all the earth. [...]

Then I heard every creature in heaven and on earth and under the earth and on the sea, and all that is in them, saying: “To him who sits on the throne and to the Lamb be praise and honor and glory and power, for ever and ever!” [...]

I watched as the Lamb opened the sixth seal. There was a great earthquake. The sun turned black like sackcloth made of goat hair, the whole moon turned blood red, and the stars in the sky fell to earth, as figs drop from a fig tree when shaken by a strong wind. The heavens receded like a scroll being rolled up, and every mountain and island was removed from its place.

Then the kings of the earth, the princes, the generals, the rich, the mighty, and everyone else, both slave and free, hid in caves and among the rocks of the mountains. They called to the mountains and the rocks, “Fall on us and hide us from the face of him who sits on the throne and from the wrath of the Lamb! For the great day of their wrath has come, and who can withstand it?”

—Revelation 5:6, 5:13, and 6:12-17
The Lamb
Boss The Lamb
Found In
The Dark Room
Dropped Items
Final Boss Chest (Ending 15)

The Lamb is the final boss of the Dark Room.


The Lamb is a two part fight. The first phase transitions into the second phase when the boss reaches 50% health.

Phase 1Edit

The Lamb has a variety of attacks in this phase:

  • Fires a 2-to-4-way shot directly at the player.
  • Unleashes a scatter shot of many small explosive tears in a random fashion.
  • Fires a constant stream of non-explosive shots in a circular pattern around itself like Mom's Heart.
  • Shoots a semi-circular pattern around itself consisting of smaller, non-explosive shots that will split apart once they make contact with any surface like The Parasite.
  • Fires 4 Brimstone lasers like Head of Krampus that can rotate clockwise or counterclockwise.
  • Fires up to five lines of non-explosive shots. Spawns attack flies during this attack.
  • Fires a 3-way or a V shot that will consist of homing tears towards Isaac. Spawns attack flies during this attack.

Phase 2Edit

Once The Lamb reaches 50% health, it will fall to the ground and its head will detach from the body. This phase has each part of The Lamb attacking independently of each other; the head gains three attacks in addition to the attacks from Phase 1, while the body only has two attacks that it will use at random intervals.

The Head's AttacksEdit

The head of the Lamb can use any of the attacks from Phase 1, but now has three additional attacks. It operates independently of the body and does not seem to change its behavior at all when the body is defeated.

  • Charges extremely quickly directly towards the player, stopping at the edge of the room.
  • Stops in place and fires a spinning Brimstone attack, similar to the Phase 1 attack. After a few seconds, the beams will begin to rotate and sweep around the room clockwise or counterclockwise.
  • Fires a large burst of homing tears at the player similar to a Monstro's Lung attack.
  • The Lamb will start moving again after each attack is finished.

The Body's AttacksEdit

The body of the Lamb is stationary and will remain wherever the Lamb was as the end of Phase 1. It does not have any of Phase 1's attacks. The body will use its attacks at random intervals and does not seem to react to anything. It will attack in the same way regardless of whether or not the head is still alive, and does not seem to attack any more often even if the player stands in its line of fire.

  • Fires a large burst of tears at the player similar to a Monstro's Lung attack. They may look like explosive or homing tears, but they have no special effects whatsoever.
  • Spawns up to 5 attack flies.
    • If the head is defeated first, the body will be able to spawn up to 25 attack flies.
  • When the body is killed, a Curse of Darkness effect will cover the entire floor for a significantly longer period of time than the effect other bosses create.

Unlockable ItemsEdit

The following items can be unlocked by beating The Lamb with the corresponding character:

In addition, beating the Lamb with a particular character will unlock the Negative Completion Mark for that character.


  • There may be a bug where using The Tick will cause the head to become invincible upon entering its second form.
  • Killing the body too early (right after stage 2 starts) will also trigger this bug.
  • If this bug occurs, exiting and continuing will reset the boss to full health allowing the boss to be killed.
  • If The Lamb is shooting projectiles and you damage it over half of its health, it will continue to fire until dead or it has finished its attack.
  • Killing the body in around 5 seconds will make the body stand inside of the chest, making you unable to reach it (and end the game). You can fix this by going in and out of the room.


  • The music that plays during this battle is titled The Fallen Angel.[1]
  • The Lamb is a subtle reference to the name of the original Binding of Isaac's DLC expansion, "the Wrath of the Lamb". Due to the absence of any mention of a Lamb in the original game, this may be the character eponymous with The Wrath of the Lamb expansion pack.
  • One of the Fortune Teller's fortunes states "Your soul is hidden deep within the darkness". This may be a reference to the Lost's unlockable item for defeating the Lamb, which is The Soul. The Soul could be considered "hidden deep within the darkness" because The Lamb is the boss of the Dark Room, and you have to beat it with the hidden character in order to unlock it.
  • The Vs. Screen introduction depicts the Lamb with solid black bones, but in-game the Lamb actually has pure white bones.





Bosses Boss Monstro
Basement MonstroGeminiDingleLarry Jr.The Duke of FliesGurglingsFistulaStevenFamine
Cellar Gurdy Jr.PinWidowBlighted OvumThe HauntDingleLarry Jr.The Duke of FliesGurglingsFistulaFamine
The Caves ChubGurdyGurdy Jr.Mega MawMega FattyDark OneC.H.A.D.Pestilence
Catacombs The HollowThe HuskPeepPolycephalusThe Carrion QueenThe WretchedDark OnePestilence
The Depths The CageMonstro IIThe AdversaryThe GateLokiGishWarMom
Necropolis The BloatThe Carrion QueenMask of InfamyThe WretchedThe GateLokiWarMom
The Womb Mr. FredScolexTeratomaMama GurdyThe BloatLokiiDeathConquestMom's HeartIt Lives
Utero BlastocystDaddy Long LegsTeratomaMama GurdyThe BloatLokiiTriachnidDeathConquestMom's HeartIt Lives
Sheol The FallenSatan
Dark Room The LambMega Satan
Cathedral Isaac
The Chest ???Mega Satan
Devil Room Krampus
Angel Room Angel
Levels 1-5/7 The FallenThe Headless Horseman
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